Blind screw anchors of the kind referred to are commercially available for securing articles to hollow panels, for example, now widely used for partition walls in industrial buildings, office blocks and domestic dwellings. A hole is drilled through the skin, usually plasterboard or hardboard, at the accessible side to permit introduction of the anchor, which is then set by pulling the threaded end toward the head to collapse the links. Such pulling can be effected either by the screw which will subsequently be used to secure the article or by a threaded mandrel of a suitable tool. On collapse, the links spread out to hold the skin of the panel against the head of the anchor. The head may have prongs arranged to penetrate the skin to prevent the anchor from rotating when a screw is threaded into it.
A blind screw anchor of the aforementioned kind is available commercially under the Registered Trademark "MOLLY". It is a reliable and effective fastener which is easy to install. It is made from three separate sheet metal parts, namely, a head, a shank, and a nut portion. All three parts are welded together. The manufacturing cost of the fastener is thus relatively high.